Kofu Air Raid Site (Tanabata Air Raid)

The Bombing of Kofu (甲府空襲, Kōfu Kūshū), commonly known as the Tanabata Air Raid (七夕空襲, Tanabata Kūshū), was one of the most devastating incendiary attacks on a medium-sized Japanese city during World War II. On the night of July 6-7, 1945, United States Army Air Forces B-29 Superfortress bombers launched a massive firebombing raid that destroyed the heart of Kofu, the capital of Yamanashi Prefecture.

The attack began at 23:47 on July 6 when the first B-29s appeared over the Kofu Basin. A total of 131 bombers from the USAAF's bases in the Mariana Islands — elements of the 39th and 330th Bombardment Groups — struck the city over approximately two hours, with the last bombs falling at 01:48 on July 7. The aircraft approached via Suruga Bay, using Cape Omaezaki as a navigation waypoint, before turning inland toward the Kofu Basin. Due to cloud cover, most bombers released their payloads using radar guidance from altitudes between 13,400 and 14,600 feet.

The ordnance consisted primarily of M-47 napalm incendiary bombs and E-46 incendiary cluster bombs — the same types employed in the devastating March 10, 1945 firebombing of Tokyo. The densely packed wooden buildings of Kofu's city center ignited rapidly, and the unique basin geography amplified the destruction: the mountains surrounding the Kofu Basin trapped heat and superheated air, creating a ferocious firestorm that consumed entire neighborhoods.

The human toll was staggering. According to a comprehensive 1974 survey, 1,127 civilians were killed (499 men and 628 women), 1,239 were injured, and 18,094 buildings were destroyed, leaving approximately 74% of the city's urban area in ashes. Many residents had believed Kofu would be spared, reasoning that its mountain-ringed location provided natural protection and that the city lacked significant military-industrial targets. This false sense of security had attracted numerous evacuees from Tokyo, including prominent literary figures such as Osamu Dazai and Masuji Ibuse, and contributed to inadequate civil defense preparations. Air raid shelter construction was further hampered by the area's high groundwater table.

Today, Kofu has been entirely rebuilt, but the memory of the Tanabata Air Raid is preserved through several memorial sites across the city, including the Yamanashi Peace Museum (山梨平和ミュージアム), the Ishizue Jizo Memorial at Ichirenji Temple, and the War Victims Memorial at Tsutsujigazaki Cemetery. Annual memorial ceremonies are held each July to honor the victims. The Kofu Air Raid stands as a powerful reminder of the devastating impact of strategic bombing on civilian populations during World War II.